Field
The disclosed concept pertains generally to a faceplate assembly and, more particularly, to a faceplate assembly, such as, for example, a lighted faceplate display wherein selected portions of the faceplate may be selectively illuminated. The disclosed concept further pertains to circuit breaker modules having such a lighted faceplate assembly.
Background Information
Circuit breakers are used, for example, in aircraft electrical systems where they not only provide over-current protection but also serve as switches for turning equipment on and off. Aircraft or subminiature circuit breakers, for instance, are typically relatively small to accommodate the relatively high-density layout of aircraft circuit breaker panels, which make circuit breakers for numerous circuits accessible to a user. Aircraft electrical systems can consist, for example, of hundreds of circuit breakers, each of which is used for a circuit protection function as well as a circuit disconnection function through a push-pull handle.
The circuit breaker push-pull handle is moved from in-to-out in order to open the corresponding load circuit. This action may be either manual or, else, automatic in the event of an overload or fault condition. If the push-pull handle is moved from out-to-in, then the load circuit is re-energized. If the load circuit had been automatically de-energized, then the out-to-in operation of the push-pull handle corresponds to a circuit breaker reset action.
It is known to mount a number of conventional aircraft or aerospace circuit breakers in a module. The module includes a frame assembly defining an enclosed space in which the circuit breakers are disposed. The module includes a faceplate having indicia (text, numbers, symbols, and lines grouping selected circuit breakers) thereon indicating the purpose or function of each circuit breaker. To ensure the indicia is visible, especially at night or other dark conditions, the module is typically backlit. That is, the faceplate is a translucent planar member having two coatings on one side. The first coating disposed on the planar member is a light color, typically white, and the second coating, which is disposed on the first coating, is a dark color, typically black or grey. The indicia are created by etching the indicia in the second coating. That is, a portion of the second coating is removed so that the first coating is visible. Further, a light is disposed in the module frame assembly enclosed space. The light illuminates the inner side of the planar member. Where the second coating is intact, the light does not pass through the planar member, the indicia however, is illuminated. Thus, there are dark portions of the faceplate, i.e. where the second coating is intact, and illuminated portions of the faceplate, i.e. the indicia. It is noted that the indicia are typically formed from thin lines and do not allow a substantial amount of light to pass therethrough. That is, the indicia are illuminated and easily visible, but the light is not sufficient to illuminate other portions of the outer face of the faceplate or adjacent objects. An incandescent light bulb in the module frame assembly enclosed space illuminates all indicia and, as such, cannot be used to illuminate a specific indicia, such as a warning indicia. This is a problem.
The planar member also includes a number of openings through which each circuit breaker push-pull handle passes so that handles are on the user side of the module. Thus, the push-pull handle may be the only visible portion of the aerospace circuit breakers during normal usage. Accordingly, the push-pull handle may also be used to indicate the status of the aerospace circuit breaker. For example, the push-pull handle may include a brightly colored, stem that is only visible when the push-pull handle is in the out position. Thus, if the push-pull handle is typically in the in position during use, a tripped circuit breaker in the out position would be noticeable as the brightly colored stem would be visible.
Typically, the indicia associated with each circuit breaker is spaced above or below, or otherwise adjacent to, each exposed handle. Thus, the planer member immediately adjacent the opening through which a handle passes is typically covered by the second coating. That is, the faceplate is mostly dark, other than the indicia.
There is room for improvement in such circuit breaker modules. For example, at night, or during other dark conditions, the push-pull handle brightly colored stem may not be visible as the module may be in the dark. Further, light from the indicia is insufficient to illuminate the push-pull handle. Thus, a circuit breaker may trip, causing the brightly colored portion of the stem to be exposed, but the pilot may not see the brightly colored portion of the stem due to poor lighting. Further, aircraft electronics may be able to determine other conditions associated with a circuit breaker other than a tripped status, i.e. a need for a test or diagnostic. The module described above does not provide a device for communicating such needs.
Thus, there is a need for a circuit breaker module, and more specifically a faceplate assembly for a circuit breaker module, that provides a clearly visible indication of a circuit breaker's condition.